where Ia and CC subscripts refer to the two different SN types.
For Ia we assume \(y_{\rm Ia} = 0.7 \, M_\odot \)  and \(k_{\rm Ia} = 1.3\times 10^{-3} \, M_\odot ^{-1}\) . [1]}, see also [2]}, suggest a possible higher
\(k_{\rm Ia}\)  value of \(2.5\times 10^{-3} \, M_\odot ^{-1}\) .
For CC SN we assume \( y_{\rm CC} = 0.074 \, M_\odot \)  and \( k_{\rm CC} = 1.0 \times 10^{-2} \, M_\odot ^{-1}\)  . Substituting the above values in Eqn. REF  and dividing by the solar abundance we get \(\mathcal {Y}_{\rm Fe,\odot }= 0.93 \, Z_\odot \) .
An higher estimate can be obtained by assuming that SNIa rate is higher in clusters with respect to the field [3]}, [4]}, [5]}. If, following [5]}, we assume a SNIa rate per unit mass of \(k_{\rm Ia} = 3.1 \pm 1.1 \times 10^{-3} \, M_\odot ^{-1}\) , we derive \(\mathcal {Y}_{\rm Fe,\odot }= 2.34\pm 0.62 \, Z_\odot \) .
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